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The NASA North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) ship and aircraft field campaign deployed to the western subarctic Atlantic between the years 2015 and 2018. One of the primary goals of NAAMES is to improve the understanding of aerosol–cloud interaction (ACI) over the Atlantic Ocean under different seasonal regimes. ACIs currently represent the largest source of uncertainty in global climate models. During three NAAMES field campaigns (NAAMES-1 in November 2015, NAAMES-2 in May 2016, and NAAMES-3 in September 2017), multiple 10 h science flights were conducted using the NASA C-130 aircraft to measure marine boundary layer aerosol and cloud properties. The standard flight pattern includes vertical spirals where the C-130 transitioned from high altitude to low altitude (and vice versa), collecting in situ measurements of aerosols, trace gases, clouds, and meteorological parameters as a function of altitude. We examine the data collected from 37 spirals during the three NAAMES field campaigns, and we present a comprehensive characterization of the vertical profiles of aerosol properties under different synoptic conditions and aerosol regimes. The vertical distribution of submicron aerosol particles exhibited strong seasonal variation, as well as elevated intra-seasonal variability depending on emission sources and aerosol processes in the atmospheric column. Pristine marine conditions and new particle formation were prevalent in the wintertime (NAAMES-1) due to low biogenic emissions from the surface ocean and reduced continental influence. Higher concentrations of submicron aerosol particles were observed in the spring (NAAMES-2) due to strong phytoplankton activity and the arrival of long-range-transported continental plumes in the free troposphere with subsequent entrainment into the marine boundary layer. Biomass burning from boreal wildfires was the main source of aerosol particles in the region during the late summer (NAAMES-3) in both the marine boundary layer and free troposphere.

Labor supply is a critical issue for many industries and the industry comprising the pork value chain is no exception. Training and development of thought leaders and decision makers is critical for the long-term sustainability of the industry. Therefore, the National Pork Board (NPB) has targeted funding for professional student education and training in critical areas of study in both traditional and non-traditional disciplines (see table). The intended outcome of this program is highly trained professionals who possess skills and abilities that have direct application to the pork value chain. While results of specific, swine-related research projects are not the desired outcome, the NPB recognizes that research is a critical component of professional student training. The training must go beyond what is typical of a mentor-mentee relationship between a faculty member and graduate student and include leadership, communication, and interpersonal relationship skills in a team environment is an outcome of the program. Additionally, training must include significant opportunity for “in residence” with a cooperating company. Since its inception, the Pork Scholars Program has made 18 awards to 7 institutions for the training of 9 MS and 9 PhD students. Of the 18 awards, 12 are focused on applied swine nutrition and production, 2 in reproductive physiology and one each in animal welfare, veterinary science, genetics, and agriculture economics and mathematics. Through the Pork Scholars Program, the NPB provides continuous support for future industry leaders to consistently add value to the industry.

Lidar and polarimeter aerosol microphysical retrievals require calculating single-scattering properties that are computationally expensive. One of the easiest ways to speed up these calculations is to use a look-up table. Two important currently available look-up tables were created about 15 years ago. Advancements in modern computational hardware allows us to create a new look-up table with improved precision over a larger range of aerosol properties. In this new and improved Lorenz-Mie look-up table we tabulate the light scattering by an ensemble of homogeneous isotropic spheres at arbitrary wavelengths starting from 0.355 μm. The improved look-up table covers spherical atmospheric aerosols with radii in the range of 0.001–100 μm, with real parts of the complex refractive index in the range of 1.29–1.65, and with imaginary parts of the complex refractive index in the range of 0–0.05. We test twelve wavelengths from 0.355 to 2.264 μm and find that the elements of the normalized scattering matrix as well as the asymmetry parameter, the aerosol absorption, backscatter, extinction, and scattering coefficients are precise to within 1% for 99.99% of cases. The look-up table together with C++, Fortran, Matlab, and Python codes are freely available online.

Measurements of the vertical profile of atmospheric aerosols and aerosol optical and microphysical characteristics are required to: 1) determine aerosol direct and indirect radiative forcing, 2) compute radiative flux and heating rate profiles, 3) assess model simulations of aerosol distributions and types, and 4) establish the ability of surface and space-based remote sensors to measure the indirect effect. Consequently the ASR program calls for a combination of remote sensing and in situ measurements to determine aerosol properties and aerosol influences on clouds and radiation. As part of our previous DOE ASP project, we deployed the NASA Langley airborne High Spectral Resolution Lidar (HSRL) on the NASA B200 King Air aircraft during major field experiments in 2006 (MILAGRO and MaxTEX), 2007 (CHAPS), 2009 (RACORO), and 2010 (CalNex and CARES). The HSRL provided measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm). These measurements were typically made in close temporal and spatial coincidence with measurements made from DOE-funded and other participating aircraft and ground sites. On the RACORO, CARES, and CalNEX missions, we also deployed the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). RSP provided intensity and degree of linearmore » polarization over a broad spectral and angular range enabling column-average retrievals of aerosol optical and microphysical properties. Under this project, we analyzed observations and model results from RACORO, CARES, and CalNex and accomplished the following objectives. 1. Identified aerosol types, characterize the vertical distribution of the aerosol types, and partition aerosol optical depth by type, for CARES and CalNex using HSRL data as we have done for previous missions. 2. Investigated aerosol microphysical and macrophysical properties using the RSP. 3. Used the aerosol backscatter and extinction profiles measured by the HSRL to characterize the planetary boundary layer height (PBL) and the transition zone thickness, for the RACORO and CARES and CalNex campaigns as we have done for previous campaigns. 4. Investigated how optical properties measured by HSRL vary near clouds. 5. Assessed model simulations of aerosol spatial distributions and optical and microphysical properties.« less

The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent analysis and archival of the data, and the presentation of results in conferences, workshops, and publications. DOE ASR field campaigns supported under this project included - MAX-Mex /MILAGRO (2006) - TexAQS 2006/GoMACCS (2006) - CHAPS (2007) - RACORO (2009) - CARE/CalNex (2010) In addition, data acquired on HSRL airborne field campaigns sponsored by other agencies were used extensively to fulfill the science objectives of this project and the data acquired have been made available to other DOE ASR investigators upon request.

The effects of Doppler shifting caused by the mean wind field on the separability of gravity wave spectra are analyzed using the gravity wave models developed recently by Gardner et al. (1993). If the intrinsic joint vertical wave number (m) and temporal frequency (ω) spectrum is separable, Doppler effects associated with even small mean winds will destroy separability of the observed joint (m, ω0) spectrum, particularly at high vertical wave numbers. The effect can have a substantial impact on the measured m-spectrum especially when the observations are not sensitive to the lowest or highest observed frequencies. Data averaging or low-pass temporal filtering can result in substantial reduction of the spectrum magnitude at high m values while data prewhitening or high-pass temporal filtering can result in significant distortion of the spectrum at low m values. These results have important implications for observational tests of the various gravity wave spectral models.

Gravity wave models for the horizontal wave number spectra of atmospheric velocity and density fluctuations are derived by assuming that both saturated and unsaturated waves obey the polarization and dispersion relations and that the joint vertical wave number (m) and temporal frequency (ω) spectrum is separable. In the wave number region h* = ƒm*/N ≤ h ≤ m*, where h = (k2 + l2)1/2, k is the zonal wave number, l is the meridional wave number, ƒ is the inertial frequency, N is the buoyancy frequency, and m* is vertical wave number of the largest scale saturated wave, the model predicts that the two-dimensional isotropic spectrum is proportional to h−(p+1) and the one-dimensional spectra are proportional to k−p and l−p when the temporal spectrum is proportional to ω−p. In the saturation region h, k, l, m > m*, the spectra are proportional to h−(q+1), k−q and l−q when the saturated m spectrum is proportional to m−q. The joint (k, l, m) and (k, l, ω) model spectra are not separable. The models are consistent with existing observations of horizontal wave number spectra in the lower stratosphere and upper mesosphere.

In the paper “Hyperspectral aerosol optical depths from TCAP flights” by Y. Shinozuka et al. (Journal of Geophysical Research: Atmospheres, 118, doi:10.1002/2013JD020596, 2013), Tables 1 and 2 were published with the column heads out of order. Tables 1 and 2 are published correctly here. The publisher regrets the error.

The UIUC CEDAR Rayleigh/Na lidar was operated for approximately 160 h on 30 nights in January, March, and April 1989 at the Arecibo Observatory (18°N, 67°W) as part of the AIDA Act '89 Campaign. During this period 38 quasi-monochromatic gravity waves were observed in the stratopause region (25-55 km) and 62 waves were observed in the mesopause region (80–105 km). The event rates in both regions are approximately half those observed at the midlatitude site of Urbana. The characteristics of the waves in both regions are similar. Measured vertical wavelengths range from 1.1 to 17 km, vertical phase velocities from −6 to −270 cm s−1, observed periods from 5 min to 65 h, and amplitudes (relative atmospheric density variations) 0.4% to 17%. The wave amplitudes in the stratopause region are on average half the values for waves in the mesopause region with similar periods and vertical wavelengths. Vertical wavenumber spectra of density perturbations in both regions exhibit power-law dependencies with slo...

Mice that are ets variant gene 5 (ETV5) null (Etv5(-/-)) undergo the first wave of spermatogenesis but lose all spermatogonial stem cells (SSCs) during this time. The SSC loss in Etv5(-/-) mice begins during the neonatal period, suggesting a role for ETV5 in SSC self-renewal during this period. Herein, we show that Etv5 mRNA was present in perinatal mouse testis and that ETV5 was expressed in fetal Sertoli cells and by germ cells and Sertoli cells during the neonatal period. Transplantation of Etv5(-/-) germ cells failed to establish spermatogenesis in W/W(v) mice testes, indicating that germ cell ETV5 has a key role in establishment or self-renewal of transplanted SSCs. The SSC self-renewal is stimulated by glial cell-derived neurotrophic factor (GDNF) acting through the RET/GDNF family receptor alpha 1 (GFRA1) receptor complex in SSCs. Immunohistochemistry, quantitative PCR, and laser capture microdissection revealed decreased RET mRNA and protein expression in spermatogonia of neonatal Etv5(-/-) mice by Postnatal Days 4-8, indicating that disrupted GDNF/RET/GFRA1 signaling may occur before initial spermatogonial stem/progenitor cell decrease. Etv5(-/-) spermatogonia had reduced proliferation in vivo and in vitro. Decreased cell proliferation may cause the observed decreases in the number of type A spermatogonia (Postnatal Day 17) and daily sperm production (Postnatal Day 30) in Etv5(-/-) mice, indicating quantitative impairments in the first wave of spermatogenesis. In conclusion, ETV5 is expressed beginning in fetal Sertoli cells and can potentially have effects on neonatal Sertoli cells and germ cells. In addition, ETV5 has critical effects on neonatal spermatogonial proliferation, which may involve impaired signaling through the RET receptor.

Sporadic Na (Nas) layers have been observed frequently at low- and high-altitude sites primarily in the Northern Hemisphere. Nas layers are very dense and very thin (∼1 km FWHM) and can form over periods ranging from a few minutes to several hours. Radar and lidar observations by our group at Arecibo have shown conclusively that Nas layers are linked to the formation of sporadic E (Es) layers. Large Nas events were observed on several flights during ALOHA-90 to extend over horizontal distances of approximately 1800 km. Atmospheric tides and gravity waves were observed to have an effect on the vertical motion of these layers. We describe the 22 March event which was observed from Maui (21°N) to near the equator (5°N) and the 27 March event which was observed from Maui (156°W) to almost the International Date Line (∼172°W).

The airborne Na lidar and Christmas Island MF radar were used to measure the spectra of gravity wave density and wind perturbations during ALOHA-90 on the 25 March mission. Wave activity was especially strong near Christmas Island with measured wind variances between 1,000 and 1,400 (m/s){sup 2}. The vertical and meridional wave number spectra of horizontal wind perturbations exhibited power law shapes with slopes of {minus}3.17 and {minus}2.22, respectively. The temporal frequency spectrum appeared to be influenced by strong Doppler effects and had a shallow slope near {minus}1. The magnitudes of the spectra were 4.9 {times} 10{sup 5} (m/s){sup 2}/(cyc/m) at the vertical wave number 2{pi}/(4 km), 8.4 {times} 10{sup 6} (m/s){sup 2}/(cyc/m) at the meridional wave number 2{pi}/(200 km) and 7 {times} 10{sup 5} (m/s){sup 2}/(cyc/m) at the temporal frequency 2{pi}/(1 h).

This white paper presents the scientific motivation and preliminary logistical plans for a proposed ASP field campaign to be carried out in the summer of 2007. The primary objective of this campaign is to use the DOE Gulfstream-1 aircraft to make measurements characterizing the chemical, physical and optical properties of aerosols below, within and above large fields of fair weather cumulus and to use the NASA Langley Research Center’s High Spectral Resolution Lidar (HSRL) to make independent measurements of aerosol backscatter and extinction profiles in the vicinity of these fields. Separate from the science questions to be addressed by these observations will be information to add in the development of a parameterized cumulus scheme capable of including multiple cloud fields within a regional or global scale model. We will also be able to compare and contrast the cloud and aerosol properties within and outside the Oklahoma City plume to study aerosol processes within individual clouds. Preliminary discussions with the Cloud and Land Surface Interaction Campaign (CLASIC) science team have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign, suggesting collaboration would benefit both teams.

Arctic stratospheric aerosols and clouds have been observed during the SOLVE/THESEO-2000 campaign in the winter 1999/2000 with the newly developed LaRC aerosol lidar with 532 nm parallel and perpendicular and 1064 nm parallel backscattering channels on board the NASA DC-8 research aircraft. The lidar data have been evaluated by means of the T-matrix method for the backscatter by non-spherical particles in the micron-size range. Similar to previous winters several polar stratospheric cloud (PSC) types have been observed: (1) type 2 PSCs which consist of water ice particles (typical particle radii r=1–2 μm); (2) type 1b PSCs which are consistent with ternary solution droplets (r≈0.3 μm); and (3) enhanced type 1a clouds which are most likely composed of nitric acid trihydrate (NAT) particles (r=1.5–0.3 μm). Besides these well-known PSC types other very thin type 1a clouds have been found, that can be explained only in terms of very large particles (r>3 μm). This finding corroborates in situ measurements, whi...

We present vertical and horizontal wave number spectra of density perturbations in the upper stratosphere (25–40 km) and the upper mesosphere (∼80–105 km) inferred from ∼45 hours of airborne Na/Rayleigh lidar observations in the vicinity of Hawaii. The mean density variance is (0.92%)2 for the upper stratosphere and (6.1%)2 and for the upper mesosphere. The mean vertical shear variance and Richardson's number for the upper mesosphere are (6.1%/km)2 and 0.69, respectively. The observed vertical wave number m and horizontal wave number k spectra exhibit power law dependencies. The mean slopes of the vertical wave number spectra are −2.5 for the upper stratosphere and −3.1 for the upper mesosphere. The mean slope of the horizontal wave number spectra is −1.9 for the upper mesosphere. The mean characteristic vertical and horizontal wavelengths inferred from the spectra are 13.4 and 5810 km, respectively. In all cases the magnitudes of the upper stratosphere m spectra are more than an order of magnitude smaller than those of the upper mesosphere at all observable scales. In the stratosphere the m spectra exhibit significant energy at low wave numbers that are less than the values expected for the characteristic wave numbers. This suggests the presence of gravity wave sources capable of generating significant energy at long vertical scales. The source is believed to be geostrophic adjustment of the jet stream. A large-amplitude, highly coherent, quasi-monochromatic, short horizontal scale (λh ∼ 16 km) oscillation in the Na layer was observed on the March 22 flight. The oscillation resembled short horizontal scale structures often observed in OH airglow images and was found to be consistent with a gravity wave interpretation.

During the early morning of January 16, 1989 the Arecibo 430 MHz incoherent scatter radar and the University of Illinois CEDAR Na lidar were operated simultaneously for several hours at the Arecibo Observatory, Puerto Rico (18°N, 67°W). At approximately 0425 LST a sporadic E (Es) layer began forming near 101 km altitude and moved steadily downward reaching an altitude of 99 km by 0500 LST. The electron abundance of the Es layer increased rapidly from approximately 3×109 cm−2 at 0510 LST to approximately 6×109 cm−2 by 0530 LST. During this same time period a sporadic Na (Nas) layer formed at the same altitude as the Es layer. Both the Es and Nas layers moved upwards together between 0530 and 0600 LST before dissipating at an altitude of 101 km. The high correlation between the altitude and abundance variations of the two layers strongly suggests that the Nas layer formation is related to the Es layer and may involve Na cluster ion chemistry.